If you are arriving in April I assume it will prob be May or so before you depart. Late Autumn/Winter weather in the south of Oz is a thing to be avoided (unless you particularly looking for chiils n spills).
Head north young man (although NSW south coast is quite scenic) up NSW coast and up Queensland Eastern coast. Beautiful climate, spectacular scenery and lifestyle...beaches, snorkelling, resort islands, seafood etc much within walking distance of airfields. Avoid Gulf of Carpentaria and Northern Territory coastlines as looooooooong way with little to see or do.